Talking to me Bb? You're preaching to the choir then... I wouldn't expect anyone to need calmag in organics either.
All good WC...
No, I was generally speaking here. Thanks for pointing out the ratio in the CAL/MAG. I've never used it and so I would know little of its use and makeup other than with organic soil we have other methods to resolve the same issue without having to spend money and get into the bottled paradigm.
Reason for not getting back to you right away cause I wanted to figure out what the deal is with the Cal/Mag and Epsom Salt.
Epsom Salt, I tried it a few times in soil when I was younger learning organic soil. An old friend of my mothers had a greenhouse and always supplied my mother and us with peppers and tomato starts from clone - the heirloom varieties. She was an organic farmer too and showed me how to add a tbs of Epsom Salt to the hole when transplanting tomatoes outdoors. Supposedly to help with blossom end rot.
Was a disaster for me and I never used it again other than a foot bath which BTW, we humans apparently need a lot more Mg than plants do for some reason. Could be that pesky thing in plants called Chlorophyll. We humans don't have much of that unless
The reasoning behind that is the chemical make up of Chlorophyll (a) = C55H72O5N4Mg <-- only one atom of Mg there so plants don't use much.
So plants need very little Mg - Epsom Salts = Magnesium Sulfate. I would suggest that when we use Epsom Salt and plant responds well, it's likely due to the "sulfate" portion of the mix. Sulfur is a critical element needed for plant health and probably one of THE most over looked elements.
Epsom Salt is actually heptahydrate sulfate mineral epsomite (MgSO4·7H2O). The organic version is actually created from ... wait for it...... Dolomite limestone! Go figure that eh?
I guess my issue with the use of Cal/Mag and or Epsom Salt (wonder why is always capitalized?), is we are talking organic gardening and also mainly container growing. We will quickly have WAY too much Magnesium if used as part of a regular watering routine or even 2-3 times a cycle. Then I would have to dump soil and re-populate containers with fresh soil. I think that is counter productive even IF it was considered organic.
With the use of Cal/Mag and or Epsom Salt, Mg toxicity will quickly become an issue in containers with a properly mixed soil.
Here's a little info bomb - Epsom Salt is ONLY allowed to be used in Organically labeled food IF the soil has been tested and the results for Mg are in the LOW range. Very unlikely in container gardening ... more of an issue with Corn that's been grown in the same field for 6-7 years in a row. We know that's not going to be organic anyway. So no point to use it and that's my point.
Also ONLY in the USA is it considered Organic with a soil test with Mg deficient soil (everywhere else in the world NOT organic). I think Dolomite Limestone is an organic amendment...slow release.. I don't advocate its use due to the Ca/Mg ratio of 2:1 since the proper ratio is 7:1 or higher.
I'm going to offer up a much better alternative to a "possible" Cal/Mag deficiency... Some cannabis plants exhibit early yellowing in flower. Everyone jumps on Cal/Mag Epsom Salt wagon... I would suggest a soil test and find out IF there's actually any issue OR maybe it's the cultivar/phenotype expressing herself naturally. Only way to tell whats what is a soil test. Think of all the pretty fall colors .. ooh la la....
Cal/Mag - Epsom Salt substitute:
1 cup of Kelp meal - soak in quart of water overnight.
In the morning put contents in a food processor and blend for 10-20 seconds/ Pour back into the quart jar and put in fridge.
Wait for the kelp and water to separate. Pour off the water into a few gallons and water in.. also can add it your IPM and spray on. Suggest 2-3 tbs per gal water... you will have extra. Use with IPM until used up.
With the kelp left over put in the fridge and every say 3rd watering add a tsp to your water ... there' s a 6 month supply of Cal/Mag+ / Espom Salt for a few pennies and it's organic.
If used as a foiler... watch out! Goodness follows and it's dramatic. Overnight result.
This solution is not going to stop senescence (yellowing leaves) but it will eliminate the "Cal/Mag" deficiency.
As an aside... don't water in Calcium. It doesn't work, I tried (why I'm not sure - I call stoner moment). Kelp Meal has Calcium...
Everyone that made it this far.... you local County Extension Service (USA) has a soil test program. It cost me $9 per test here in PA... should be similar everywhere else in the states. If anyone would like help getting a test kit mailed to you I will help you figure it out. Many states the kits are available locally. I bought kits at my local nursery the other day and will start a new thread about it when I get my results back.
